The isolation of active components from "confirmed active" plant extracts arising out of the CCNSC plant program. The Contractor carries out the fractionation of plant extracts with known antitumor activity obtained through the CCNSC plant program, and assigned to him for study. Starting with the large quantities of plants provided by CCNSC, the active agent is isolated in sufficient quantity for preliminary evaluation in the screening program. This chemical fractionation is continually guided by bioassays provided by the CCNSC.